1. Field of the Invention
The present invention relates to a system for detecting failure of manufacturing apparatuses, a method of detecting failure of manufacturing apparatuses, and a computer program product for detecting failure of manufacturing apparatuses and, more particularly, to a technology for detecting a manufacturing apparatus poor in yield from a plurality of manufacturing apparatuses which are used in parallel in a specific manufacturing process.
2. Description of Related Art
In general, a plurality of manufacturing apparatuses are often used in parallel in a manufacturing process in a production line of semiconductor devices. When the yield of lots processed by a manufacturing apparatus from among the plurality of manufacturing apparatuses is lower than those of the other manufacturing apparatuses, there is a possibility that the cause of the lower yield is inherent to the manufacturing apparatus. Therefore, in order to improve the yields of the manufacturing apparatuses, it is required that the failing manufacturing apparatus be detected early in order to analyze the cause of the lower yield. In the related art, differences in yield distributions between manufacturing apparatuses are usually analyzed without considering time axes in detecting a failing manufacturing apparatus.
However, when the plurality of manufacturing apparatuses are used unevenly in terms of time, analyzing only the differences of the yield distributions without considering the time axes may lower the capability to detect failing manufacturing apparatuses and produce false reports. Furthermore, when the number of target lots is increased in order to reduce false reports in number and raise the capability to detect failing manufacturing apparatuses, early detection of failing manufacturing apparatuses becomes difficult.